add a few more ConfigureAwaits to avoid deadlocks on WinForms / ASP.NET

Author: kjnilsson

projects/client/RabbitMQ.Client/src/client/impl/SocketFrameHandler.cs

@@ -54,7 +54,7 @@ static class TaskExtensions
     {
         public static async Task TimeoutAfter(this Task task, int millisecondsTimeout)
         {
-            if (task == await Task.WhenAny(task, Task.Delay(millisecondsTimeout))) 
+            if (task == await Task.WhenAny(task, Task.Delay(millisecondsTimeout)).ConfigureAwait(false))
                 await task;
             else
                 throw new TimeoutException();

projects/client/RabbitMQ.Client/src/client/impl/TcpClientAdapter.cs

@@ -26,13 +26,13 @@ public TcpClientAdapter(Socket socket)
 
         public virtual async Task ConnectAsync(string host, int port)
         {
-            var adds = await System.Net.Dns.GetHostAddressesAsync(host);
+            var adds = await Dns.GetHostAddressesAsync(host).ConfigureAwait(false);
             var ep = adds.First();
             #if CORECLR
             await sock.ConnectAsync(ep, port);
             #else
             sock.Connect(ep, port);
-            await System.Threading.Tasks.Task.FromResult (false);
+            await Task.FromResult(false);
             #endif
         }